1. Field of the Invention
The present invention relates to a semiconductor package that can prevent wire bonds from shifting during packaging, and more particularly to a semiconductor package that has a fixing portion in the wire bond area to position the wire bonds during packaging a semiconductor die or electric device on the substrate. The present invention also relates to a method of manufacturing a semiconductor package with wire protection to prevent the wire bonds from shifting.
2. Description of the Related Art
When molding encapsulating material for packaging a semiconductor die or an electric device on a substrate, it is found that the encapsulating material in liquid state will sweep the wire bonds and thus causes the wire bonds to contact each other. A closed circuit is formed between the wire bonds such that the semiconductor die or electric device will malfunction or be damaged since short circuit occurs as a result of the undesired closed circuit between the wire bonds. It is, therefore, always desirable to keep the wire bonds away from one another to avoid short circuit of the semiconductor die or electric device.
Taiwan Utility Model Publication No. 347573 issued on Dec. 11, 1998 discloses a method of protecting the wire bonds, and such method is illustrated in FIGS. 1 through 3 of the drawings. FIG. 1 illustrates that a semiconductor die 11 is mounted on a substrate 10, and a plurality of wire bonds 12 extend outwardly from the semiconductor die 11 to provide electrical connection between the substrate 10 and the semiconductor die 11. FIG. 2 illustrates spraying of the adhesive over the wire bonds 12 so as to reduce the exposed length of the wire bond 12. As shown in FIG. 3, when the adhesive 13 diffuses, the adhesive 13 flows outwardly to cover the wire bond 12. However, it takes a relatively long time to spray, diffuse and harden the adhesive 13.
U.S. Pat. No. 5,331,205 to Primeaux issued on Jul. 19, 1994 discloses a mold plastic package with wire protection to solve the wire sweep problem. As shown in FIG. 4, the mold plastic package includes an encapsulating material 20, a package body 21, a semiconductor die 23, a plurality of wire bonds 24, and a lead frame 26 with a plurality of leads 25. The semiconductor die 23 is mounted on a die pad 22 of the lead frame 26 and includes a plurality of bonding pads (not shown). The wire bonds 24 each provides an electrical connection between the bonding pads of the semiconductor die 23 and the leads 25 of the lead frame 26. The encapsulating material 20 that has a low coefficient of thermal expansion encapsulates the upper face of the semiconductor die 23 and all of the wire bonds 24. The package body 21 encapsulates the die 23, portions of the leads 25, and the encapsulating material 20. It is, however, found that hardening of the encapsulating material 20 still takes a long time since it must cover the die 23 and the wire bonds 24.
It is, therefore, a long and unfulfilled need to provide a semiconductor package with wire protection and with short hardening time for the encapsulating material.